Isolation rates of different mycobacterial species from Chandigarh (north India).

A total of 4958 patients, clinically suspected to have tuberculosis were screened for mycobacteria by acid fast staining and culture procedures. Mycobacterial species were isolated from 462 (9.3%) patients while acid fast bacilli were demonstrated on smear examination in 83 (1.7%) patients. Mycobacterium tuberculosis was the most common isolate (92%). Among the nontuberculous mycobacteria, M. fortuitum was isolated in 13 (2.8%), M. avium in 2 (0.4%) and M. szulgai in 1 (0.2%). In 22 individuals clinically suspected of tubercular pleural effusion, pleural biopsy specimen gave higher isolation of mycobacteria (27.3%) as compared to isolations from pleural fluid specimens (9.1%).